Mattress covers are generally known for basic protection of mattresses, and to provide a removable and cleanable encasement when soiled. As it became known that bed bugs may reside and multiply within mattresses, and come out and bite and feed off humans while they are sleeping or bite or feed through the cover, mattress covers have been developed which are intended to prevent egress or ingress of bed bugs through the mattress cover.
Bed bugs may reside not only in mattresses but in upholstery of furniture and are found in homes, theaters, luggage and vehicles, and have been carried in the clothing of people who have gotten them from any of many possible sources.
Mattress covers designed to protect against bed bugs are of great interest lately because of a recent epidemic in the United States, Europe and elsewhere of bed bugs not only in mattresses but in offices and even in seats in a large movie theater in New York City. The epidemic is so severe and widespread that, for example, New York State recently passed a law designated The Bed bug Disclosure Act which requires owners and lessors of residential space to notify new rental tenants of any bed bug infestations that have occurred in the building and in the specific rental unit during the past year, where a tenant is contemplating residence.
A recent article in The New York Law Journal dated Sep. 2, 2010 shows that complaints of bed bug infestations in New York were more than twenty times as high in 2009 as they were in 2004, the source of this information being the New York City Department of Housing, Preservation and Development.
There are a number of reasons for this epidemic, including (a) the massive amount of international travel where bed bugs are imported unwittingly by persons or in luggage, and (b) current statutes barring certain insecticides which previously tended to keep the bed bug population under control. There may be additional reasons regarding the sources of this massive infestation of bed bugs or explanations for how they are transported from place to place; however, the focus of the present application concerns first, efforts to contain bed bugs that are already in mattresses, mattress platforms and box springs, cushions, pillows, and covers and encasements therefore, and thus to prevent bed bugs from escaping to feed on humans sleeping or sitting on such articles, and second, to prevent bed bugs from entering such articles and encasements. As will be appreciated, the benefits of this invention may be utilized also for upholstered furniture and other products. Since fabrics resistant to bed bug penetration are known, the area of concern of this invention is escape of bed bugs or entry of bed bugs through the closure devices such as due to an incomplete zipper closure or a failure to properly position the zipper lockdown tab of a zipper closure.
The prior art includes numerous conventional mattress covers with zipper closures intending to address this problem, one particular example being prior art patent U.S. Pat. No. 7,552,489 disclosing a mattress cover with an inner bed bug barrier strip that is situated below the zipper tracks, extends a short distance in the proximal direction from the closed end of the zipper toward the open end, and is sewn to the cover along parallel paths outward of the zipper tracks to form a tunnel below the tracks, intended to block or isolate bed bugs.
In another prior art mattress cover the zipper tracks of the zipper closure section extend beyond the mattress cover encasement, and the extending zipper track portion folds back on itself with Velcro® type fastening.